预偏补偿悬臂端位移在钢桁架拱桥跨中无应力合拢施工中的应用

Application of pre-deviation compensation for cantilever end displacement in non-stress closure construction at mid-span steel truss arch bridge

重庆朝天门长江大桥是目前世界上最大跨度的拱桥,设计无应力跨径为190 m+552 m+190 m,从边支点向跨中悬臂安装。采取预偏施工技术,调整边、中支点高差及位移,补偿合拢口高差及位移,成功实现桁拱跨中无应力合拢,可供类似工程施工参考。

Chongqing Chaotianmen Yangtze River Bridge is the largest arch bridge in span currently in the world with a design non-stress span of 190 m＋552 m＋190 m, installed from side bearing point to mid-span cantilever. This paper uses pre-deviation construction technique to successfully achieve non-stress closure at the mid-span by adjusting the elevation difference and displacement between side and middle bearing points to compensate the elevation difference and displacement at the closure opening, serving as a reference for the similar engineering construction.